Traditional telephone networks operate to complete a call dialed by a calling party to a called party by establishing a fixed path, commonly referred to as a “circuit,” between the calling party and called party for the duration of the call. The process of establishing a circuit between the calling and called parties, referred to as “circuit-switched” telephony commences upon receipt of the call at a local switch in the network serving the calling party. Toll calls and special featured calls (i.e., calls dialed to an 500, 700, 800, 888, 877, 866 or 900 number, and Software Defined Network (SDN) calls) typically pass from the local switch to a toll switch in an Inter-exchange Carrier (IXC) network, such as the AT&T Network. The receipt of a special featured or SDN call in the IXC network triggers a query to a database referred to in the AT&T network as a Network Control Point (NCP), but often referred to in other telecommunications networks as a Service Control Point (SCP).
The NCP/SCP contains routing information that instructs the ingress toll switch how to handle the call in accordance with the calling and/or called party numbers. The call routing instructions translate the dialed number to a Logical Routing Number associated with the called party to enable the IXC network to route the call to that party. Called parties that receive large numbers of special featured calls often maintain call centers in multiple locations to handle such calls. To facilitate call handling, the called parties that maintain such call centers often request that their telecommunications service provider provide varying call treatment at different times for calls originating from different locations. For example, a called party that maintains call centers in different time zones may want its communications service provider to route calls that originate during certain hours to one call center, but route calls originating at other times to a different call center. In addition to, or in place of prescribing a “time-of-day” routing plan, a called party may also prescribe a day-of-the-week routing plan requiring its communications carrier route calls to different destinations depending on the day of the week. Some called parties may also prescribe geographic routing restrictions to restrict receipt of calls from certain jurisdictions.
Subscribers that have traditionally enjoyed circuit-switched telephony service have begun to migrate to packet-based telephone service. Thus, a subscriber may have an IP PBX at one call center linked to a backbone IP network to receive and originate Voice-Over IP calls, while maintaining a circuit-based PBX at another call center linked to a circuit-switched network for originating and receiving Plain Old Telephone Service (POTS) calls. Ideally, a subscriber that enjoys such “hybrid” communication service would like to preserve its prescribed routing plan for all calls regardless whether the calls originate or terminate at a packet-based or circuit-based PBX. Unfortunately, present day providers of communications service lack the ability to readily offer customers that have hybrid service the ability to use their legacy (circuit-switched) routing plan for all calls. As a result, the customer often must replicate their legacy routing plan for packet-based calls, i.e., calls that originate or terminate at a packet-based PBX, to the extent that the communications service provider even offers the ability to provide varying call treatment for packet-based calls.
Thus, there is need for a technique for handling subscriber calls in a telecommunications network in accordance with the subscriber's routing plan that overcomes the aforementioned disadvantages.